[Micturition disorders following spinal anesthesia of different durations of action (lidocaine 2% versus bupivacaine 0.5%)].

Disturbances of micturition following spinal anaesthesia are considered to be rare and harmless side effects of this technique. For this reason, we set up a prospective study to investigate their incidence, characteristics and intensity. Our special interest was directed at the influence of the duration of action of local anaesthetics. METHODS. In a randomized, double-blind study, two groups, each consisting of 73 trauma surgical and orthopaedic patients, received isobaric spinal anaesthesia with either lidocaine 2% or bupivacaine 0.5%. From the 1st to the 3rd postoperative day, the patients were interviewed daily and asked specifically about disturbances of micturition. RESULTS. The two groups were comparable in terms of clinical data, spinal anaesthesia and surgery. Disturbances of micturition occurred only during the first 24 h and were observed in a total of 42%. They were about twice as frequent after bupivacaine (56%) as following lidocaine (27%). After bupivacaine there was a higher rate of difficult micturition or complete inability to micturate in the presence of an urge to urinate, carbachol medication and catheterization of the urinary bladder. Sex and age had no influence on the incidence. A history of disturbances of micturition increased their frequency. DISCUSSION AND CONCLUSIONS. Disturbances of micturition are the most common side effect of spinal anaesthesia during the first 24 h after surgery. Their higher frequency following the longer acting bupivacaine may be evidence of longer lasting blockade of the efferent sacral parasympathetic fibers innervating the detrusor vesicae muscle, leading to inhibition of bladder voiding. The consequences of these disturbances, if not correctly managed, may be distension of the urinary bladder with ensuing infection and loss of tone of the detrusor muscle. Various measures are recommended: choice of the longer acting local anaesthetic only if necessary, careful control of bladder filling, restrictive infusion of fluids, early mobilization, carbachol, catheterization in good time, prophylactic placement of an indwelling catheter in patients with previous disturbances.